Out invention pertains to a coded carrier remote control system. More particularly, this invention relates to a coded carrier remote control system including a new and novel arrangement to coordinate and synchronize the operation of such a system when the communication channel from the control office branches at a remote junction location to follow separate paths to two different remote terminal locations.
Coded carrier remote control systems have been previously used in the remote control of railroad traffic systems. Such coded carrier is used in lieu of the older coded direct current systems to utilize various new types of communication channels and to allow longer distances of transmission between the control office and remote locations of a single system. One specific railroad traffic control installation required expansion to handle additional traffic mileage. This added stretch of track branches from the original main track route at a location along the way, that is, it diverges short of the original remote terminal. It was desirable to control the entire track length, that is, the old main and the new branch, by the existing remote control system with the necessary modifications to add additional controlled stations. These modifications require synchronization and coordination of system operation between the stations along the two branch channels and the control office. Such synchronization is particularly required during the transmission from the remote locations of indications of the conditions of the apparatus in order that such conditions may be recorded and displayed at the control office. While specific modifications will vary between the various specific types of coded carrier remote control systems which might be used under such a situation, certain basic principles pertain to all types of coded remote control operation.
Accordingly, an object of our invention is a coded carrier remote control system which includes the necessary synchronizing and coordinating apparatus to provide single system operation between the control office and a number of remote stations located along separate branches of the communication channel.
Another object of our invention is a novel synchronizing and coordinating arrangement at the remote junction location of two or more branches of the communication channel for a coded carrier remote control system which provides control of the transmission of control and indication functions between the central control office and the various stations located along each branch of the communication channel.
A further object of the invention is apparatus for synchronizing the operation of a coded carrier remote control system in which some of the remotely located stations are positioned along a branch of the main communication channel, which branch diverges at a junction remote from the control office.
Yet another object of the invention is a synchronizing arrangement for a coded carrier remote control system which assures priority of transmission to control codes carrying control or command functions from the central office and the transmission of only one indication code at a time from the various stations located along at least two branches of the system communication channel.
A still further object of our invention is apparatus for synchronizing and coordinating the operation of a coded carrier remote control system in which at least one branch communication channel, which connects more than one station into the system, diverges at a junction point intermediate the control office and the remote terminal station of the main communication channel.
Other objects, features, and advantages of our invention will become apparent from the following specification and appended claims when taken in connection with the accompanying drawings.